Whose fault is it? Is it not the fault of government and policy makers and educationists?
The people who went to these mountains many of them were well educated and still they went for a stupid trek of "char dham". When such a large croud goes on the mountains, it brings all the bad factors with it including pollution and other pressure related with the population. Now just to worship some "Idols",, people will make the upstream water and environment dirty.
Rather than having nature based scientific eco tourism for children and adults there is a blind faith of "Idol worshiping", where people in their millions go to source of rivers and polluted the rivers. Each river has been made a drain and every city starting from the mountains is putting their dirt and sewage in the rivers.
If we can not keep out sources of water clean and pure, i can not understand, what else can this country keep clean. In the end all the dirty water comes down to the plains and we are polluting it from its source.
Not only that we are exploiting the nature by constructing roads and buildings in old crude way of blasting the way out and doing rampant construction to cater the need of people visiting the mountains and Idol worshiping places.
See the delima, at one end people worship these rivers at the other end they put their dirt in it.